1. Technical Field
This specification relates to the fabrication of a laminate and more particularly, although not exclusively to the preparation of an adhesive layer with uniform thickness for laminating plates.
2. Background Art
Lamination by adhesive is commonly used for making devices including those for optics, integrated circuitry or any of a wide variety of other applications. Typically, such lamination includes disposing a layer of liquid adhesive onto one laminate layer, subsequently joining another laminate layer onto the disposed liquid adhesive, applying pressure on the joined layers, and curing the adhesive between the laminate layers. With low viscosity adhesives, such as those used for thin film applications, the thickness of the disposed liquid adhesive film can be easily changed during the lamination process. For example, in glass-to-glass lamination, a composite layer of glass may experience sag and/or a non-uniform application of pressure with another composite layer of glass.
To provide for some consistency in the thickness of an adhesive layer, conventional lamination techniques variously fabricate, position, or otherwise include spacer structures in the same layer as the adhesive material. For example, in LCD sealing adhesive lines, glass or plastic beads are commonly used to control the adhesive thickness. However, the inclusion of such spacer structures within an adhesive layer has associated costs or other inefficiencies. Moreover, such spacer structures may have undesirable characteristics in optical applications, where an index of refraction of a spacer structure is different than the index of refraction of the adhesive material and/or the index of refraction of an adjoining laminate layer.